INDIGO,
As I read, stall by definition is a reduction of the lift generated by an airfoil. If you are loosing lift, technically you start going downhill, thus your load factor has to be less than 1G.
From this, can we say that the stall speed is the speed at which the aircraft is no longer able to maintain level flight for a set of fixed parameters?
In this case, there are two separate speeds we can look at: one is the stall speed (less lift, nose drop, less load factor), the other one, slightly higher (maybe just one knot or so), would be the minimum steady speed for level flight , i.e. no loss of lift at his point. That is before the aircraft stalls.
Does this make sense?